EXPERT REACTION: Sunscreen chemicals absorbed into bloodstream - more safety studies needed

Embargoed until: Publicly released:

Living in Australia, we are all well aware of the necessity of greasing up with sunscreen at the beach, but US researchers suggest that we might be taking in more of the active ingredients into our blood than the US Food and Drug Administration's (FDA) thresholds. The team tested six of the main active ingredients in lotions, sprays, and pump varieties of sunscreens, and say the quantities found in the blood would mean the FDA would require additional safety studies. The team emphasises that their findings do not mean people should stop using sunscreen, but instead more research is needed to figure out the significance of these levels in our blood.

Journal/conference: JAMA

DOI: 10.1001/jama.2019.20747

Organisation/s: US Food and Drug Administration

Funder: The study was funded by the US Food and Drug Administration (FDA).

Media Release

From: JAMA

Bottom Line: A randomized clinical trial with 48 healthy volunteers assessed the absorption of six active ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate and octinoxate) in four sunscreen products formulated as lotion and sprays (aerosol, nonaerosol and pump). This study builds on a prior trial from Food and Drug Administration (FDA) researchers published by JAMA in 2019. In this trial, all six tested active ingredients administered in four different sunscreen formulations were absorbed and had blood concentrations that surpassed the FDA threshold for potentially waiving some of the additional safety studies for sunscreens. Researchers emphasize the findings don’t mean people should refrain from using sunscreen, which can help to prevent skin cancer and protect the skin. More research is needed to determine the effect of exposure to sunscreen ingredients. This study was conducted indoors in a clinical research setting and participants weren’t exposed to direct sunlight during the seven days they remained at the clinic. A change in study design from an indoor to an outdoor setting would better represent real-life sunscreen application. The study also wasn’t designed to assess the absorption difference by formulation or skin types.

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Expert Reaction

These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.

Professor Ian Rae is an expert on chemicals in the environment at the School of Chemistry at the University of Melbourne. He is also an advisor to the United Nations Environment Programme on chemicals in the environment and isĀ former President of the Royal Australian Chemical Institute.

We know that chemical substances can be absorbed through the skin. It's a phenomenon that we take advantage of when applying nicotine patches, or aspirin-like medications ('liniment') that can ease aching muscles. So it's no surprise that the UV-absorbing chemicals in sunscreens can be taken into the body.

As in earlier investigations, the present report concerns very heavy application of sunscreen. The absorption process is slow, and it is reported that residues remaining on the skin can be absorbed slowly over the next day or so.

In laboratory tests most of the sunscreen chemicals can act as hormone mimics, potentially affecting development and the immune system, but whether these effects can be demonstrated in whole bodies, and whether the use of sunscreens can produce higher concentrations than the body can safely deal with, are as-yet-unanswered questions.

The editors of the journal that carried this report are rightly cautious on these points, and the Editorial they provide is a very good statement of where the science is at. Looking at the results, an Australian scientist might say 'that's interesting, but I'd like to know more about it before I can judge how dangerous the sunscreens are.

Skin cancer is probably a greater danger than sunscreen'. A less-cautious consumer might opt for a mineral sunscreen, perhaps without realizing that the minerals, zinc oxide and titanium oxide, can also be absorbed through the skin.

Last updated: 22 Jan 2020 11:24am
Declared conflicts of interest:
None declared.
Heather Walker is Chair of the Skin Cancer Committee for Cancer Council Australia

It’s important that Australians continue to use sunscreen alongside other forms of sun protection to prevent skin cancer. Skin cancer kills over 2,000 Australians each year and two in three Australians will be diagnosed by the age of 70. 

This is a small study of 48 individuals conducted in a lab environment that didn’t mimic real-life conditions. The researchers behind this study themselves say that these results should not discourage people from using sunscreen. In Australia, sunscreens are closely regulated by the Government’s Therapeutic Goods Administration to make sure they are safe and effective – but sunscreen alone is not enough. When the UV is 3 or above, everyone needs to slip, slop, slap, seek (shade) and slide (on sunglasses).

Last updated: 21 Jan 2020 5:43pm
Declared conflicts of interest:
Cancer Council produces a range of sunscreens, the profits from which are reinvested in research, prevention and support
Professor Rodney Sinclair is Professor of Dermatology at the University of Melbourne and Director of Epworth Dermatology

Sunscreen, along with hats, clothing and shade are measures advocated by dermatologist to reduce skin exposure to ultraviolet radiation and the consequential risk of skin cancer. Sunscreen is recommended when the UV index is greater than or equal to 3. Sunscreen is not recommended is the UV index is less than 3. This week, sunscreen is recommended across the entire continent of Australia for all people who will be outside for more than 20 minutes between the hours of 10 am and 4 pm.

Australian sunscreens are regulated by the Australian Government Department of Health through the Therapeutic Goods Administration (TGA) and must meet strict testing standards. Many ingredients have been in common use for many years with no safety concerns. Recently the Federal Drug Agency (the USA equivalent of Australia’s TGA) identified that some sunscreen agents are absorbed through the skin at levels higher than previously realised and at levels higher than which previous testing has confirmed safety. This does not mean that they are unsafe at these levels, merely that additional testing is required. The FDA will now conduct more research to determine the maximum levels of sunscreen ingredients that are safe to use. 

The TGA will monitor this and consumers will be alerted if there are any safety concerns identified by the FDA. Until then, people should continue to protect themselves and their children from the harmful effects of UV radiation by using shade, clothing hats and where necessary sunscreen.

Last updated: 21 Jan 2020 12:38pm
Declared conflicts of interest:
None declared.
Bruce Armstrong AM is a consultant in Cancer Causes and Prevention, Epidemiology, Environmental Health, Health Services as an Adjunct Professor in the School of Global and Population Health at The University of Western Australia, as well as an Emeritus Professor from the School of Public Health at the University of Sydney

This publication adds to an earlier study by the same investigators, which showed that four active ingredients of sunscreens were absorbed into the bloodstream at unexpectedly high levels. It confirms the results of the earlier study.

It also shows that two additional sunscreen-active ingredients were also absorbed into the bloodstream and that all six chemicals were absorbed in a regime for applying the sunscreens more like that used in real life than previously.

Increased levels persisted for up to 10 days when using most sunscreens and in most participants, and longer in some.

The US Food and Drug Administration sponsored these studies and has requested more evidence for the safety of sun-screening chemicals. This evidence is urgently needed.

In the meantime, it cannot be said, with any certainty, that the application of these chemicals to human skin is safe.

The chemicals studied in these research projects were avobenzone, oxybenzone, octocrylene, ecamsule, homosalate, octisalate, and octinoxate.

Australians who use sunscreens containing potentially absorbable sunscreen-active chemicals and are concerned about their safety can reduce or cease their use of such sunscreens by:

  1. Increasing their practice of other sun protection measures, which are detailed here https://www.cancer.org.au/preventing-cancer/reduce-your-risk/be-sunsmart.html; and/or
  2. Changing to use of a sunscreen product that contains only zinc oxide or titanium dioxide as sunscreen active chemicals.
Last updated: 21 Jan 2020 12:35pm
Declared conflicts of interest:
None declared.

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